I like weird saving throws. In my house rules, one is called “dragon breath, explosions” and another is called “rays, wands”—a bit of implied setting for my players.

For monsters, on the other hand, I like to have just a single save. I use the Swords & Wizardry method: 19 - HD, plus or minus 2 for magic susceptibility or resistance, rarely a minus 4 for even more resistance.